In a manufacturing process of a semiconductor device in which a laminated structure of an integrated circuit is formed on a surface of, for example, a semiconductor wafer (hereinafter, referred to as a “wafer”) as a substrate, a liquid processing step is performed to process the surface of the wafer using a liquid, for example, to remove fine dust or a natural oxide film on the surface of the wafer using a cleaning liquid such as, for example, chemical liquid.
There has been known a method using a processing fluid in a supercritical state or a subcritical state (hereinafter, collectively referred to as a “high pressure state”) when removing a liquid attached to the surface of the wafer in such a liquid processing step.
Japanese Patent Laid-Open Publication No. 2013-012538 discloses a method of drying a substrate, including bringing a liquid attached on a pattern formed on a substrate in a processing container into contact with carbon dioxide (processing fluid) in a supercritical state or a subcritical state to discharge a part of the carbon dioxide in the supercritical state from which the liquid is extracted in the processing container from a discharge line, and removing the liquid while continuing to supplying new carbon dioxide in a supercritical state from a fluid supply line without significantly lowering a liquid extracting ability by carbon dioxide in a supercritical state in the processing container.
In this case, if carbon dioxide is used as a processing fluid for a long period of time while suppressing a discharge amount of the carbon dioxide, consumption of the processing fluid may be lowered.